QLEDs have good luminescent properties and researchers from the Institute for Basic Science within Seoul National University have shown they can be folded into complex 3D structures such as butterflies, airplanes, and pyramids. The work is reported in a Nature Electronics papers
The same research team revealed a basic QLED device in 2015 (see Quantum LEDs stick to the skin ). That device had a thickness of 3-microns and exhibited mechanical flexibility allowing it to be applied to wearable devices such as electronic tattoos.
The IBS researchers have now reported three-dimensional foldable QLEDs, which can be transformed into various user-customized 3D structures, such as butterflies, airplanes, and pyramids. This technology could be significant for foldable and rollable displays and dynamic three-dimensional display of visual information.
The foldability is based an additional fabrication process that used a power-controllable carbon dioxide pulsed laser and silver-aluminum alloy-based etch-stop layers This allowed partial etching of the epoxy film deposited on the QLED surface without damaging the underlying QLED. By thinning the epoxy layer it is possible to define preferential deformation lines along which the device folds.
Minimum radii of curvature down to 50 microns were achieved using this selective etching technique and the QLED material was able to maintain stable light-emitting performance after enduring being folded 500 times.
"By fabricating the passively driven, 3D foldable QLED arrays composed of 64 individual pixels, we have shown the possibility of developing displays with greater complexity in the future," said Kim Dae-Hyeong, the vice-director of the Center for Nanoparticle Research within the IBS, in a statement.
Related links and articles:
Three-dimensional foldable quantum dot light-emitting diodes , Nature Electronics . DOI: 10.1038/s41928-021-00643-4